1. Field of the Invention
The present invention relates to methods for manufacturing composite materials and, particularly, to a method for manufacturing a carbon nanotube composite material.
2. Discussion of Related Art
Carbon nanotubes (CNTs) are tube-shaped structures composed of graphite. CNTs have a high Young's modulus, a high thermal conductivity, and a high electrical conductivity, and other properties. Due to these and the other properties, it has been suggested that CNTs can play an important role in fields such as microelectronics, material science, biology, and chemistry.
A kind of thermally conductive material that conducts heat by using CNTs has been developed. The thermally conductive material is formed by injection molding and has numerous CNTs dispersed in a matrix material. The thermally conductive material includes a first surface engaging with an electronic device, and a second surface engaging with a heat sink. The second surface has a larger area than the first one, so that heat can be uniformly spread out to the larger second surface. However, the thermally conductive material formed by injection molding is relatively thick, which increases a bulk of the thermally conductive material and reduces its flexibility. Furthermore, CNTs are dispersed in the matrix material randomly and are multidirectional in orientation, which results that heat tends to spread uniformly through the thermally conductive material, retaining much of the heat within the heat transfer material. Therefore, the heat does not spread efficiently from the first surface engaged with the electronic device to the second surface engaged with the heat sink.
Therefore, a method for manufacturing a thin carbon nanotube composite material, with controlled nanotube orientation within one or more desired patterns and, thus, with good thermal/electrical conductivity, is desired.